Make your own free website on

Isopropyl Mercaptan

Isopropyl mercaptan, also called 2-propanethiol, is a clear liquid with a smell that can be described as nothing more than nightmarish. It is produced by the simple action of sodium hydrosulfide on isopropyl bromide. Obviously getting the precursors is harder than performing the reaction. The only reason I produced it was as an amusement (due to the horrendous smell, not dissimilar to a dead skunk). The amusement will quickly disapate if one were to spill this anywhere in their house.

C3H7Br + NaHS ----> C3H7SH + NaBr

Sodium hydrosulfide 250ml RBF
Isopropyl Bromide Reflux condensor to fit flask
Ethanol Distillation equipment
  Water bath equipment

Into the 250ml round bottom flask, place either 16grams of anhydrous sodium hydrosulfide, or 25-30g of hydrated sodium sulfide. You want an excess of sodium hydrosulfide, otherwise there will be residual isopropyl bromide in your product, since they very close boiling points. To this, add roughly 100ml of ethanol. Begin heating it on a water bath, swirling occaisonally. Measure out 25ml of isopropyl bromide, and add it to this. Attach your reflux condensor and start the flow of water through the condensor, while still gradually heating on the water bath. Reflux this for 2 hours (longer will never hurt), then stop heating. You will notice a white residue covering the inside of your flask. This is sodium bromide.

Set your flask up for simple distillation. I was not overly concerned with purity or yeild, since I only wanted this as a novelty item. If you're not concerned with purity, then heat the water bath to 75C and hold it there. Continue holding it, and eventually your product will begin to distil. Keep collecting it until there is no longer any visible boiling in the flask. Theoretical yeild is 20g. I obtained 15.7 this way, so 78.5% yeild.

If you are concerned about purity, heat the water bath to 85C and hold it there. Continue holding it and eventually your product will begin to distil. Keep distilling it until you've obtained rougly 40-50ml of distillate. Fractionally distil this, collecting only the fraction coming over between 51C and 57C. This is your pure isopropyl mercaptan. Theoretical yeild is 20g.


Distilation - Here you can see the white NaBr residue. This was jerry-rigged as you can see. I only have a 1000ml distilation setup at the moment, and that is far too large for small amounts like this.

Product - This is a picture of the mercaptan. You can see it is yellow, I think this was from the latex tubing joint I used in the above jerry-rigged distilation set-up. The color did not affect the hellish, apetite depressing smell one bit though!